These are seldom seen, but a sufficient number are now recorded and figured to enable us to study the nature of the defect. Sir W. Fergusson seems the only English surgeon who has observed this rare condition, the majority of recorded cases hailing from Germany or France. As we shall see hereafter, this defect is due to the non-closure of the cleft between the outermost part of the intermaxilla and the maxilla itself, and occupies the position which was claimed up to recent years as that of an ordinary harelip.
In several of the cases noted red cicatrices ([Fig. 18]) rather than actual clefts ([Figs. 19 and 20]) were present. The defect begins at the free margin of the upper lip, and usually at the spot whence starts the ordinary harelip cleft; but occasionally from the angle of the mouth. It then trends upwards and outwards, leaving the nose entire, and skirts round the ala nasi to reach its upper limit at the middle of the lower eyelid which is cleft, or at the inner canthus. The eye itself may show a coloboma iridis, usually downwards and inwards. The facial skeleton may be divided or not; sometimes a large opening into the antrum exists (Hasellmann,[16] Kraske[17]). No incisor teeth are developed on the outer side of the cleft, the first tooth seen being the canine. On the inner border of the cleft lip there is usually a marked frænulum, often smaller, however, than the normal median frænum.
This deformity may be unilateral or bilateral (Guersant, Meckel), more frequently the former; and is not uncommonly associated with macrostoma of the same or opposite side of the face (Guersant, Pelvet[18]), as seen in [Fig. 20].
Albrecht[19] records a most interesting case in a newly born pup ([Fig. 21]) of double clefts extending from the lip margin upwards not only into the nostril, but also towards the eye on either side, i. e. a double associated harelip and facial cleft. The specimen is taken from the Royal Veterinary College of Brussels.
Fig. 21.—Front view of a young puppy’s head from a preparation in the Veterinary College of Brussels, showing double harelip with double partial facial cleft. (After Albrecht.)
a. Central portion of upper lip, corresponding to internal nasal process. b. Ala nasi, corresponding to external nasal process. c. Outer portion of upper lip, from superior maxillary process. d. Harelip cleft. e. Facial cleft.
Fig. 22.—Macrostoma, showing the cleft in the cheek prolonged upwards and backwards by a reddish cicatrix to a lateral loss of substance of the cranial wall. (Sutton.)